Current Science

Santanu Talukder ¹, Praveen Kumar ², Rudra Pratap ¹

Affiliations
1 Centre for Nano Science and Engineering, Indian Institute of Science, Bengaluru 560 012, IN
2 Department of Materials Engineering, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

Electromigration, mostly known for its damaging effects in microelectronic devices, is basically a material transport phenomenon driven by the electric field and kinetically controlled by diffusion. In this work, we show how controlled electromigration can be used to create scientifically interesting and technologically useful micro-/nano-scale patterns, which are otherwise extremely difficult to fabricate using conventional cleanroom practices, and present a few examples of such patterns. In a solid thin-film structure, electromigration is used to generate pores at preset locations for enhancing the sensitivity of a MEMS sensor. In addition to electromigration in solids, the flow instability associated with the electromigration-induced long-range flow of liquid metals is shown to form numerous structures with high surface area to volume ratio. In very thin solid films on nonconductive substrates, solidification of flow-affected region results in the formation of several features, such as nano-/micro-sized discrete metallic beads, 3D structures consisting of nanostepped stairs, etc.

Keywords

Electromigration, Fabrication and Pattern Formation, Material Transport, 3D Micro-/Nano-Structures.

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